Microfluidic Time-Delay Valve Mechanism on Paper-Based Devices for Automated Competitive ELISA

Paper-based technologies have been drawing increasing attentions in the biosensor field due to their economical, ecofriendly, and easy-to-fabricate features. In this paper, we present a time-delay valve mechanism to automate a series of procedures for conducting competitive enzyme-linked immunosorbent assay (ELISA) on a paper-based device. The mechanism employs a controllable time-delay valve, which has surfactants to dissolve the hydrophobic barriers, in a fluid pathway. The valves can regulate the liquid and sequentially deliver the sample flow for automating ELISA procedures in microchannels. Competitive ELISA is achieved in a single step once the sample, or small molecule pesticide (e.g., Imidacloprid), is applied onto the paper-based device with a comparable sensitivity to plate-based competitive ELISA. The results further demonstrate the appositeness of using paper-based devices with the valve designs for on-the-go ELISA detection in agriculture and biomedical applications.

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Application of ELISA to Retail Survey of Aflatoxin B1 in Peanut Butter

Journal of Food Protection ◽

10.4315/0362-028x-49.10.792 ◽

1986 ◽

Vol 49 (10) ◽

pp. 792-795 ◽

Cited By ~ 13

Author(s):

BHANU P. RAM ◽

L. PATRICK HART ◽

RICHARD J. COLE ◽

JAMES J. PESTKA

Keyword(s):

Immunosorbent Assay ◽

Aflatoxin B1 ◽

Coefficient Of Variation ◽

Simple Procedure ◽

Peanut Butter ◽

Competitive Elisa ◽

Routine Screening ◽

Enzyme Linked Immunosorbent Assay

A simple procedure was devised for the routine screening of aflatoxin B1 (AFB1) in peanut butter using enzyme-linked immunosorbent assay (ELISA). Peanut butter samples (5 g) were artificially contaminated with AFB1 and extracted by blending with 25 ml of 55% methanol and 10 ml of hexane. The extract was filtered and aqueous filtrate analyzed by a direct competitive ELISA. Recovery of AFB1 added to peanut butter samples ranged from 85 to 112%, with an average inter-well coefficient of variation of 18.4%. The inter-assay coefficient of variation was 22.7%. Using this procedure, only 3 of 63 commercial samples of peanut butter had detectable levels (>5.0 μg/kg) of AFB1.

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Development of an Immunoglobulin M (IgM) Capture Enzyme-Linked Immunosorbent Assay for Detection of Equine and Swine IgM Antibodies to Vesicular Stomatitis Virus

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.8.3.475-481.2001 ◽

2001 ◽

Vol 8 (3) ◽

pp. 475-481 ◽

Cited By ~ 10

Author(s):

En-min Zhou ◽

Jose Riva ◽

Alfonso Clavijo

Keyword(s):

Vesicular Stomatitis Virus ◽

Immunosorbent Assay ◽

Polyclonal Antibodies ◽

Competitive Elisa ◽

Immunoglobulin M ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Igm Antibodies ◽

Vesicular Stomatitis ◽

Elisa Plate

ABSTRACT An immunoglobulin M (IgM) capture enzyme-linked immunosorbent assay (MC-ELISA) was developed for the detection of primary infection of vesicular stomatitis virus (VSV) in equine and swine sera. The test was based on the use of biotinylated sheep antibodies against equine or swine IgM molecules bound to a streptavidin-coated ELISA plate. The captured IgM antibodies were detected by application of antigens prepared from the New Jersey and the Indiana VSV serotypes (VSV-NJ and VSV-IN, respectively) and mouse polyclonal antibodies against VSV-NJ and VSV-IN. The MC-ELISA was compared to a competitive ELISA (C-ELISA) and the standard microtiter serum neutralization (MTSN) assay by testing serum samples from horses and pigs experimentally infected with VSV-NJ or VSV-IN. The MC-ELISA detected specific homologous IgM antibodies from equine and swine sera as early as 5 and 4 days postinfection (DPI), respectively, and as late as 35 DPI. The MTSN test also detected antibodies as early as 5 DPI and as late as 160 DPI. In a similar fashion, the C-ELISA detected antibodies from 6 to 7 DPI and as late as 160 DPI. These results demonstrated that the MC-ELISA is a useful test for serodiagnosis of primary VSV infection in horses and pigs.

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The Development of a Quantitative ELISA for Aflatoxin B1 in Ground Peanuts Using Antibodies Isolated From the Yolk of a Laying Hen

Journal of Food Protection ◽

10.4315/0362-028x-57.11.1022 ◽

1994 ◽

Vol 57 (11) ◽

pp. 1022-1024 ◽

Cited By ~ 4

Author(s):

SUZHEN LI ◽

RONALD R. MARQUARDT ◽

ANDREW A. FROHLICH ◽

HAO XIAO ◽

JAMES R. CLARKE

Keyword(s):

Immunosorbent Assay ◽

Aflatoxin B1 ◽

Laying Hens ◽

Egg Yolk ◽

Laying Hen ◽

Competitive Elisa ◽

Enzyme Linked Immunosorbent Assay ◽

Coating Antigen ◽

Extraction Protocol

Antibodies directed against Aflatoxin B1 (AFB1) were produced in laying hens, isolated from egg yolk and applied in an enzyme-linked immunosorbent assay (ELISA) for AFB1 in ground peanuts. The ELISA sensitivity was improved by reduction of the amount of the coating antigen absorbed onto the microplate well surfaces. The main aflatoxins B1, B2, G1, G2, M1, aflatoxicol, sterigmatocystin were found to cross-react in the competitive ELISA, 100, 25, 23, 4, 0, 0, 0%, respectively. Aflatoxin B1 could be reproducibly detected and quantified in spiked ground peanuts at levels greater than 5 ppb using a hexane and methanol solvent based peanut extraction protocol.

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Evaluation of Primary Binding Assays for Presumptive Serodiagnosis of Swine Brucellosis in Argentina

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.7.5.828-831.2000 ◽

2000 ◽

Vol 7 (5) ◽

pp. 828-831 ◽

Cited By ~ 8

Author(s):

P. Silva Paulo ◽

A. M. Vigliocco ◽

R. F. Ramondino ◽

D. Marticorena ◽

E. Bissi ◽

...

Keyword(s):

Immunosorbent Assay ◽

Fluorescence Polarization ◽

Competitive Elisa ◽

Agglutination Test ◽

Serological Diagnosis ◽

Enzyme Linked Immunosorbent Assay ◽

Binding Assays ◽

Brucella Suis ◽

Fluorescence Polarization Assay ◽

Two Populations

ABSTRACT An indirect enzyme-linked immunosorbent assay (IELISA), a competitive ELISA (CELISA), and a fluorescence polarization assay (FPA) for the presumptive serological diagnosis of swine brucellosis were evaluated using two populations of swine sera: sera from brucellosis-free Canadian herds and sera from Argentina selected based on positive reactions in the buffered antigen plate agglutination test (BPAT) and the 2-mercaptoethanol (2-ME) test. In addition, sera from adult swine from which Brucella suis was isolated at least once for each farm of origin were evaluated. The IELISA, CELISA, and FPA specificity values were 99.9, 99.5, and 98.3%, respectively, and the IELISA, CELISA, and FPA sensitivity values relative to the BPAT and the 2-ME test were 98.9, 96.6, and 93.8%, respectively. Actual sensitivity was assessed by using 37 sera from individual pigs from which B. suis was cultured, and the values obtained were as follows: BPAT, 86.5%; 2-ME test, 81.1%; IELISA, 86.5%; CELISA, 78.5%; and FPA, 80.0%.

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A Competitive Enzyme-Linked Immunosorbent Assay for Detection of Bovine Milk in Ovine and Caprine Milk and Cheese Using a Monoclonal Antibody against Bovine β-Casein

Journal of Food Protection ◽

10.4315/0362-028x-60.1.64 ◽

1997 ◽

Vol 60 (1) ◽

pp. 64-66 ◽

Cited By ~ 26

Author(s):

G. ANGUITA ◽

R. MARTÍN ◽

T. GARCÍA ◽

P. MORALES ◽

A. I. HAZA ◽

...

Keyword(s):

Monoclonal Antibody ◽

Immunosorbent Assay ◽

Binding Sites ◽

Bovine Milk ◽

Microtiter Plate ◽

Competitive Elisa ◽

Quantitative Detection ◽

Enzyme Linked Immunosorbent Assay ◽

Caprine Milk ◽

Mouse Immunoglobulin

A competitive ELISA (enzyme-linked immunosorbent assay) was performed to detect and quantify bovine milk in ovine and caprine milk and cheese using a monoclonal antibody (AH4 MAb) against bovine β-casein. Ovine or caprine milk and cheese containing bovine milk were added simultaneously with the AH4 MAb to the wells of a microtiter plate that had been previously sensitized with commercial bovine β-casein. The bovine caseins in milk or cheese samples compete with the bovine β-casein bound to the plate for the AH4 MAb binding sites. Further immunorecognition of AH4 MAb bound to the bovine β-casein immobilized onto the plate was attained with rabbit anti-mouse immunoglobulin conjugated to peroxidase. Subsequent enzymic conversion of the substrate showed clear differences in absorbance values during assay of mixtures of ovine and caprine milk and cheese containing various amounts of bovine milk. The competitive ELISA developed in this work allows the quantitative detection of bovine milk in ovine and caprine milk and cheese samples in the range of 0.5 to 25% of substitution.

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Small-Molecule Sensing: A Direct Enzyme-Linked Immunosorbent Assay for the Monosaccharide Kdo

Angewandte Chemie International Edition ◽

10.1002/anie.201003435 ◽

2010 ◽

Vol 49 (44) ◽

pp. 8173-8176 ◽

Cited By ~ 9

Author(s):

Karin Mannerstedt ◽

Anita M. Jansson ◽

Jody Weadge ◽

Ole Hindsgaul

Keyword(s):

Small Molecule ◽

Immunosorbent Assay ◽

Enzyme Linked Immunosorbent Assay

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Enzyme linked immunosorbent assay (ELISA) for the determination of protein-A

Bioscience Reports ◽

10.1007/bf01114968 ◽

1986 ◽

Vol 6 (11) ◽

pp. 933-936 ◽

Cited By ~ 8

Author(s):

P. J. Considine ◽

P. Duggan ◽

A. Eadie

Keyword(s):

Immunosorbent Assay ◽

Protein A ◽

Competitive Elisa ◽

Routine Screening ◽

Enzyme Linked Immunosorbent Assay ◽

Culture Supernatants

A competitive ELISA for the determination of protein-A concentration in culture supernatants is described. The sensitivity of the assay is 50 ng/ml and it may be used to determine concentrations of protein-A up to 1000 ng/ml. The assay is specific, rapid and suitable for routine screening of protein-A producing microorganisms.

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A simple competitive enzyme-linked immunosorbent assay for the specific detection of the multiphosphorylated 1–25 β-casein fragment

Journal of Dairy Research ◽

10.1017/s0022029913000162 ◽

2013 ◽

Vol 80 (3) ◽

pp. 326-333 ◽

Cited By ~ 3

Author(s):

Akinori Kume ◽

Akina Sasayama ◽

Tetsuo Kaneko ◽

Junichi Kurisaki ◽

Munehiro Oda

Keyword(s):

Mass Spectrometry ◽

Immunosorbent Assay ◽

Dairy Products ◽

Sample Pretreatment ◽

Competitive Elisa ◽

Enzyme Linked Immunosorbent Assay ◽

Specific Detection ◽

Phosphorylated Form ◽

Casein Phosphopeptides ◽

Casein Phosphopeptide

A specific and simple competitive enzyme-linked immunosorbent assay (ELISA) was developed to determine bovine β-casein phosphopeptides (β-CPP) in casein phosphopeptides (CPP) or CPP complexes such as casein phosphopeptide amorphous calcium phosphate complexes added into dairy products. The method combines sample pretreatment designed for CPP enrichment and anti-β-CPP(f(1–25)) monoclonal antibody 1A5 (mAb 1A5). The mAb 1A5 bound specifically to the tryptic phosphopeptides from β-casein but not from αs1- or αs2-casein. Reactivity was also influenced by the extent of the phosphorylated form of serine residues. Based on the sequence-specific recognition and contribution of phosphorylated serine residues, the epitope of mAb 1A5 was found to reside within the cluster motif Ser(P)-Ser(P)-Ser(P)-Glu-Glu and the surrounding residues in β-CPP. The competitive ELISA developed here can be used as an alternative to specialised and expensive techniques such as mass spectrometry. In particular, it is suitable for the measurement of CPP or CPP complexes in dairy products, which contain closely related endogenous molecular species.

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